1. Field of the Invention
The present invention relates to a method and an apparatus for creating a holographic stereogram for three-dimensionally recognizing a real image or a computer-created image.
2. Description of Prior Art
In general, for creating the holographic stereogram, lots of original images obtained by sequentially imaging an object from variable observatory views are recorded on one hologram recording medium as striped or dotted holographic elements. For example, as shown in FIG. 1, the holographic stereogram having only horizontal parallax information includes a plurality of original images 101a to 101e obtained by sequentially imaging an object 100 from variable observatory points in the horizontal direction on a hologram recording medium 102 as striped holographic elements.
When a person watches this holographic stereogram at a certain location with his or her one eye, he or she can watch a two-dimensional image that is a set of image information of one portion of each holographic element. When the person moves his or her eye location in the horizontal direction, he or she can watch another two-dimensional image that is a set of image information of another portion of each holographic element. Hence, when the person watches this holographic stereogram with his or her eyes, since the locations of his or her right and left eyes are slightly different from each other, the two-dimensional image appearing on the right eye is slightly different from the two-dimensional image appearing on the left eye. This slight difference offers the person with the parallax, so that the person can recognize the holographic stereogram as a three-dimensional image.
In creating the holographic stereogram, a laser beam with excellent interference are divided into two parts, one of which is a projected image (object beam) two-dimensionally modulated by an image display unit (for example, a LCD panel) and the other one of which is a reference beam. Both of the beams are condensed on each holographic element, that is a portion of a hologram recording medium composed of a sensitive material served. Then, an interference pattern is recorded as change of a refractive index of the photosensitive material at a holographic element. Each holographic elements are formed with above-mentioned process.
In order to obtain the high-quality hologram, it is effective to locate a diffuser panel close to the image display unit.
However, the location of the diffuser panel makes it impossible to cancel the noises of the resulting hologram localized to infinity.